1. Field of the Invention
The present invention relates to a process for surface-mounting a microwave package, which includes an electronic chip, on a printed circuit and to a package and a printed circuit which are designed for implementing this process.
2. Discussion of the Background
It is known practice to mount an electronic chip directly on a receiving printed circuit; it is also known practice to mount the chip on a miniature printed circuit in order to form a microwave package which is then surface-mounted on the receiving printed circuit. In both cases, it is known practice to make the connections to the receiving printed circuit by wire connections and to cover the microwave chip or package with a protective lid. However, the use of such mounting techniques in high volume is expensive since, for high operating frequencies, it requires, for making the wire connections, when furnishing the receiving printed circuit, the use of microelectronic equipment; without such equipment, it is virtually impossible, using these mounting techniques, to work at frequencies above 12 GHz.
The object of the present invention is to avoid this drawback.
This is achieved by mounting a miniature printed circuit bearing the chip on a receiving printed circuit, in which the active face of the miniature printed circuit bearing the chip is soldered to the receiving printed circuit and in which earth planes distributed over the two printed circuits form a kind of cage constituting a screen around the chip.
According to the invention, what is proposed is a process for the mounting of a microwave package on a printed circuit, characterized in that it consists in using, for the package, a microwave package having two parallel faces, a first face of which has an electronic chip, conductors connected to the chip and earth planes inserted between the conductors, and a second face of which consists of an earth plane connected to the earth planes of the first face, in producing the printed circuit in such a way that it has a first face with, in a region dedicated to the package, conductors and earth planes and a second face consisting of an earth plane connected to the earth planes of the first face of the printed circuit, the first two faces having, on the one hand, their earth planes and, on the other hand, their conductors which, in a predetermined position of the package on the printed circuit, are in one-to-one contact, in placing the package in the predetermined position and in connecting the package to the printed circuit by soldering the conductors and the earth planes in one-to-one contact.
According to the invention, what is proposed is a microwave package for the implementation of a process for mounting a package on a printed circuit, this microwave package including a miniature printed circuit with first and second faces, the first face having an electronic chip and conductors connected to the chip, and the second face consisting of an earth plane, characterized in that the first face includes earth planes, in that these earth planes are inserted between the conductors and in that the miniature printed circuit includes connections between the earth planes of the first face and the earth plane of the second face.
According to the invention, what is proposed is a printed circuit for receiving a microwave package, for the implementation of a process for mounting a package on a printed circuit, this receiving printed circuit including first and second faces, the first face including, in a receiving region, conductors and the second face consisting of an earth plane, characterized in that the first face includes earth planes in the receiving region, in that these earth planes are inserted between the conductors and in that the receiving printed circuit includes connections between the earth planes of the first face and the earth plane of the second face.